Molecules to Morphology: Developing an Understanding of Plant Evolution Through Time
Engstrom, Eric , Bowman, John L. .
Investigating the role of non-brassinosteroid sterols in plant morphogenesis.
fackel mutants exhibit a severe, often seedling lethal, phenotype, characterized at the cellular level by abnormal patterns of cell division and elongation, greatly reduced growth of the hypocotyl, generation of multiple ectopic shoot apical meristems, disorganized cotyledons and leaves, and dwarfing. FACKEL encodes a C-14 sterol reductase. fackel cells generate an altered sterol profile. Pharmacological disruption of sterol C-14 reductase activity induces a phenocopy of the fackel mutant, suggesting a direct link between disruption of normal sterol biosynthesis and the morphological phenotypes. It has been proposed that FACKEL may be required for generation of a novel sterol signal regulating the activity of START domain containing proteins, in particular the class III HD-Zip genes, which are important regulators of meristem maintenance and lateral organ polarity. We have assayed for genetic interactions between FACKEL and the class III HD-Zip gene REVOLUTA. Seedlings homozygous for the rev-9 allele exhibit a mild phenotype in the Ler background, characterized by occasional failure to produce axillary meristems. Seedlings homozygous for fackel and rev-9 exhibit notable enhancement of the fackel phenotype, consistent with a role for FACKEL in polarity establishment. To determine the subcellular location of the FACKEL protein, we constructed a FACKEL-GFP translational fusion protein. This construct complements many aspects of the fackel phenotype, though plants remain dwarfed relative to wildtype seedlings. Failure of the fusion protein to fully rescue the mutant phenotype indicates a requirement for a free C-terminal end of the FACKEL protein. FK-GFP is localized to the endomembrane and plasma membrane systems.
Log in to add this item to your schedule
Engstrom Lab Web Page
1 - The College of William and Mary, Biology, Millington Hall, Landrum Drive, Williamsburg, Virginia, 23187, United States of America
2 - Monash University, School of Biological Sciences
Presentation Type: Symposium or Colloquium Presentation
Location: Stevens 5/Hilton
Date: Wednesday, July 11th, 2007
Time: 3:30 PM